This invention relates to an electronic insect killing device, particularly to such a device which is portable and manually operated.
A conventional fly swatter for insect killing causes a lot of trouble because the user has to be skillful enough to hit the insect before it flies away. Also, the dead body of the insect becomes messy and contaminates the environment. In an outdoor environment, mosquitoes usually fly around and are not easily killed by a conventional fly swatter.
For killing the mosquitoes, a U.S. Pat. No. 2,881,554 discloses a fly swatter comprising a swatting element having a swatting surface on one side thereof comprising a wire screen of a mesh sufficiently large to allow a fly, when hit thereby, to be forced therethrough; and, on the other side of said element, a wire screen of a mesh small enough to intercept a fly passing through said first mentioned screen; said screens being parallel to and insulated from each other but so closely spaced that a fly between said screens will have a part in contact with each; a handle for said element; and means in said handle, electronically connected to said screens as terminals, for producing electricity at a voltage sufficiently high to kill a fly when in contact with both screens. Although the 2,881,554 patent can kill a mosquito when it flies into between the two screens, it results in some practical problems to be solved. Firstly, the mesh screen, especially each intersection point, blocks the insects to pass therethrough. For example, a fly when hit near any mesh intersection point, is definitely blocked out of the screen, thus it is difficult to coincidentally force the fly to pass the mesh screen when in use. Secondly, when a fly is killed between the two mesh screens, the body of the fly will be retained in between the two mesh screens and it performs as a capacitor to be charged by the voltage drop between the two mesh screens. Therefore, in practical use, if a fly is caught between the meshes, the fly swatter can not kill another incoming fly until the caught fly has been charged to be a dry body or removed. Thirdly, the mesh screens require to be woven with very high tension preventing the front screen and the rear screen to contact to each other and causing short-circuit. Fourthly, the mesh screens requires much time and effort to weave, therefore the manufacture thereof costs expensively. Fifthly, the fly swatter can only kill flies not for other insects and the flies have to be coincidentally fly between the two screens. Sixthly, the fly swatter can only kill flying flies not for other insects which fly or crawl such as attactable bees, mothes, cockroaches, ants, spiders, and so on. It is understandable that the mesh structure of Pat. No. 2,881,554 is not an efficient device for the reasons described above.
In U.S. Pat. No. 1,966,999, an apparatus for electrocuting insects is disclosed. This apparatus comprises a frame provided with a pair of spaced channel members, a plurality of insulating members, each insulating member having a body portion, an outwardly and rearwardly extending base portion in supported engagement with a channel member, and an outwardly extending flange having teeth formed by alternate deep notches and shallow notches therein, said body portion having parallel grooves in the outer face thereof in line with said notches, said base portion and flange being in spaced relation and extending substantially in parallel from the same side of the body portion, and wires extending from the teeth of an insulating member supported in one channel member to the teeth of an insulating member supported in the other channel member with alternate wires connected in pairs by offset portions lying in a common plane, said connected pairs of wires arranged alternately in deep notches and shallow notches between the teeth so as to be in insulated, interleaved relation. U.S. Pat. No. 1,966,999 uses parallel wires replacing mesh screens. However, U.S. Pat. No. 1,966,999 cannot avoid uselessness when any wire is broken. Since the wires in U.S. Pat. No. 1,966,999 are separated into two wires connected to any suitable source of high tension current, any one of them is broken resulting in a dangling portion which is apt to be short circuited with adjacent wires thus damaging the apparatus. Moreover, each of the two wires is woven through the frame with very high tension, therefore the woven parallel pattern of the wire will be damaged and lose its effect due to any broken portion of each wire. Another drawback of the U.S. Pat. No. 1,966,999 is that this apparatus is mounted in a door, or the equivalent, therefore it is not portable.
It is requisite to provide an improved structure which still works even when any portion of the exposed wire is broken.